Uppadine L H, Redman J E, Dent S W, Drew M G, Beer P D
Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford, UK.
Inorg Chem. 2001 Jun 4;40(12):2860-9. doi: 10.1021/ic001450v.
The new rhenium(I) bipyridine crown ether receptors 1-4 have been prepared and their ion pair recognition properties examined. The crystal structure of 1.KCl.2H(2)O demonstrates that potassium is coordinated by benzo-18-crown-6 and chloride is hydrogen bonded to the amide groups. Receptor 3 extracts solid KCl and KOAc into chloroform via ion pair complexation. NMR and emission titration studies with receptors 1-4 and KCl/KOAc show that cobound potassium enhances anion binding strength by electrostatic and conformational effects. Significant cooperative interactions are observed between the anion and cation sites for host 4 in CH(3)CN. This molecule coordinates potassium to form a 1:1 intramolecular sandwich complex, which preorganizes the host for acetate binding.
新型铼（I）联吡啶冠醚受体1 - 4已被制备并研究了它们的离子对识别特性。[1·KCl]（2）·2H（2）O的晶体结构表明，钾由苯并 - 18 - 冠 - 6配位，氯离子通过氢键与酰胺基团相连。受体3通过离子对络合将固体KCl和KOAc萃取到氯仿中。用受体1 - 4和KCl/KOAc进行的NMR和发射滴定研究表明，共配位的钾通过静电和构象效应增强了阴离子结合强度。在CH（3）CN中观察到主体4的阴离子和阳离子位点之间存在显著的协同相互作用。该分子使钾配位形成1:1的分子内夹心配合物，这使主体预先组织好以结合乙酸根。
